Professor Taek Lee’s Research Team (Department of Chemical Engineering) has Established a Rapid SELEX Monitoring System and Developed a Dengue Virus Biosensor Using This Technology

- Developed a step-by-step monitoring method for rapid SELEX monitoring -

- Demonstrating the feasibility of biosensors created by applying rapid SELEX monitoring method -

- Published in the internationally renowned Chemical Engineering Journal (IF: 13.3, JCR: 3.8%) -

Moonbong Jang and Hanbin Park, MSc students, along with Hyunjoon Park, a PhD student from Prof. Taek Lee's research team in the Department of Chemical Engineering, served as co-first authors in establishing an electrochemical SELEX monitoring system using the ACEF technique. They also developed a dengue virus biosensing platform using the aptamers created through this method.

Aptamers, which are composed of single-stranded DNA or RNA molecules, are gaining traction as a rival to antibodies due to their high specificity for specific molecules. Although antibodies and aptamers are similarly used in that they can both recognize specific molecules, aptamers are being utilized as an attractive alternative to antibodies due to their several unique advantages. For small molecules with low immunogenicity, antibody design can be complicated and expensive, but aptamers are easy to make. Additionally, aptamers offer the convenience of being synthesized through in vitro processes without the need for animal or cell testing, and their structural stability ensures they are less prone to denaturation at specific temperatures, making them suitable for use as stable bioprobes. Therefore, they are solidifying their role in the fields of diagnostics, therapeutics, food safety, and environmental monitoring.

However, despite the potential of aptamers, the process of generating aptamers, the systematic evolution of ligands by exponential enrichment (SELEX) process, is time-consuming, costly, and labor-intensive. SELEX is a cyclical process, requiring multiple stages of the same process, each of which is essentially accompanied by monitoring. Conventional monitoring methods typically involve labeling released DNA with specific markers such as fluorescent dyes, radioactive isotopes, or enzymes, or using electrophoresis. However, these methods face challenges due to the time required for target binding or the time-consuming nature of complex labeling procedures.

In response, Prof. Taek Lee’s research team from the Department of Chemical Engineering applied an electrochemical SELEX monitoring technique that incorporated ACEF technology to rapidly produce aptamers. Using this technique, they developed dengue virus biosensor, through which they validated the performance of the aptamers created by the method. The aptamer solutions at each stage were combined with the target material, dengue virus, and the signal changes were monitored by the SWV technique and monitored as signal changes due to changes in binding capacity. From the 9th round onwards, it was confirmed that there were no signal fluctuations, and this round was selected as the optimal condition. The binding time with the target was shortened using ACEF. ACEF generates an electric field in the solution on the electrode surface, creating a local temperature gradient, which induces microconvection in the fluid and enhances the binding events. Thus, the complex procedures involved in the monitoring stage were reduced to less than 10 minutes. The aptamers created through this process were applied to a dengue virus biosensor to evaluate their performance. The sensor demonstrated high selectivity by not binding to other biomolecules or viruses, and it showed a sensitive detection limit of 59.7 fM in a triple-distilled water dilution solution. This demonstrated an improved detection capability compared to the previously developed dengue virus aptamer, which had a detection limit of 76.7 fM. Additionally, the detection limit in 5% human serum was confirmed to be 37.0 fM, and in blind tests, it showed high reproducibility with low error rates of 3.49%, 4.33%, and 2.66%, respectively. Therefore, the rapid SELEX monitoring technique proposed by the research team effectively reduced the workload of developers by utilizing ACEF technology. Additionally, the proposed platform, which successfully developed DENV aptamers, demonstrated its potential applicability to various biosensing systems and proved that it could be expanded for use in commercial technologies and applications.

Meanwhile, this research was supported by the Korea Environment Industry & Technology Institute (KEITI, 2020003030001) through the Aquatic Ecosystem Health Management Program of the Ministry of Environment (MOE), the Industrial Core Technology Development Program (20009121) of the Ministry of Trade, Industry and Energy (MOTIE), and the National Research Foundation of Korea (NRF, 2021R1C1C1005583). The research results were published in the internationally renowned journal in the field of chemical engineering, Chemical Engineering Journal (IF: 13.3, JIF ranking: 96.2%), under the title ‘Establishment of the rapid electrochemical-SELEX monitoring system by using ACEF technique and its application to dengue virus aptasensor fabrication’ (Reference: https://doi.org/10.1016/j.cej.2024.154806).